Torque transmitting device



J. w. MARSHl Julyzs, 1939;

Y TOR'QUE 'TRANSMITTING DEvIcE Filed July 16, 1936 3 sheets-sheet 2 TTORNEYS.

July 2 5, 1939.1' J. w. MARSH l TORQUE TRANSIITTING DEVICE 3 sheets-'sheet s Filed July 16, 1956 057/222 M Mns-h INVENTOR. 19%

.A TTRNEYS.

o Paten-ted July 25, 1939 o j v2,166,961

UNITED STATES rail-Eur oFFlci: v

ToRQUE Taaznll'rme EvrcE i y i I John W. Marsh, Washington, D. C.

Application July 16, 1936, Serial No.-90,938

15 Claims.

This invention described herein may be manufactured and used by or for the Governmentv for governmental purposes, without4 the payment to me of any royalty thereon.

This invention relates to an improved mechanism for transmitting torque from a prime mover or driving member to a driven member. particularly, the invention comprehends a dual clutch mechanism including a primary clutch of the fluid or 'hydraulic type operably associated with a second clutch oi' the friction 'type in a manner suchthat the secondary or friction clutch becomes effective only ,after complete engagement of the fluid or primary clutch.

One of the objects of the invention is to provide'means for the rapid dissipation of energy during periods of excessive slippage between driv- ,ing and driven clutch members by the use of a fluid clutch, the working fluid oftwhich is circulated through a cooling medium thereby preventing excessive local heating of said fluid.

Another object of the invention is to provide a means for mechanically or frictionally engaging the driving and driven members of a power transmission with ,a minimum of shock and mechanical wear by delaying operative engagement between the mechanical or frictional surfaces of a rnechanical clutch until after a fluid clutch'has picked up and is driving the load so that the members of the mechanical clutch are required only to .pick up that fraction of, the total load represented by the difference in speed betweenthe driving and driven members of the fiuidclutch due to thev inherent slippage characteristics of the fluid clutch.

Another object of this invention is to provide means for controllably transmitting any'amount of driving torque regardless of the relative rotational speeds of the driving and driven members by manually controlling partial or complete engagement of the driven member with the driving member of the fluid clutch,

Another object of this invention is to eliminate the characteristic low speed drag, common to fluid clutches,` by providing means for complete disengagement between the driving and driven mem-v bers of the fluid clutch.

A further object of this invention is toprovide a clutch mechanism in which the gripping action or torque ltransmitting force is directly 'proportional to the torquev transmitted.

Astill further object of thisinvention is to provide means for. automatic release of the connection-between the driving and driven members when the speed of the driven member exceeds.

that of the driving member, thereby preventing damage to the driving member or prime mover due to excessivelspeed.

The clutch mechanism of this invention is designed particularly for use in instances Where More of the present invention is admirably suited is that of an automotive vehicle wherein each time the vehicle is started the clutch mechanism is called upon to dissipate energy by slippage in anv amount proportional to the. difference in speed between the vehicle drive shaft and the drive shaft of the prime mover. When the weight of the vehicle is great, relative to the power of the engine, the time required to accelerate the vehicle to the speed corresponding to 'the speed of the engine is suicient to require the dissipation of a large amount of energy with consequent excessive heating and wear on the clutch. The degree of -slippage of the clutch parts is controlled by partial engagement thereof, but the partial engagement of the clutches heretofore used is diilicult to regulate, and results in the dissipation of a larger amount of energy than necessary, or slippage of the driving wheels. The former increases the heating and wear on the clutch. The latter.

speed of thedriving member, controlled only by speed of said member. Second, no provision has been made for the complete separation of the character and one to which the clutch mechanism driving and driven members, and a drag on the o driven member always existed at low speed caused by the centrifugal action of the fluid against the driven member, and it was impossible to stop the driven member except byprovision of a separate brake .on that memberor provision to disconnect the driven memberfromthe driving shaft. Third, slippage always occurred between` driving and driven members regardless of the speed of the driving member. This was caused by the leakage of the fluid between the driving and driven members, compressibilit'y of the fluid and lack of mechanical connection. yThisresulted in reduced efficiency and the necessity for a provision to dissipate the heat generated in continuous operation.

Friction clutches have been used in the typical of heat, wear and regulation, but they present anf drawings, wherein I have illustrated preferredadded dimculty in that the load is firmly connected to the engine so that during periods when the vehicle iscoasting, the vehicle was permitted to drive the engine which,fparticu1arly in the lower gear ratios, resulted in harmful and sometimes destructive effects on the engine by overspeeding. Most attempts to correct this have included an independent over-running clutch which has not been developed in lsufllcient capacity as to` be satisfactory for heavy vehicles.

To attain the aforesaid objects. and overcome the diiilculties experienced in the past, I have provided a centrifugal action fluid clutch with the driven member capable of complete disengagement and partial or complete engagement with the driving member, and combined therewith a friction clutch which becomes automatically engaged after full engagement of the fluid clutch, thereby eliminating the slip of the fluid clutch under full load. Moreover, vI` have pro-- vided that the movement of the driven member and thefriction clutch be such that these members will be brought' into engagement as the load transmitted is increased and will be thrown out of engagement when the' speed of the driven member exceeds that of the, prime mover.

Other objects and features of this invention will become apparent and more clearly understood from the following specification when considered in connection with the accompanying embodiments of the invention. It is to be understood, however, that these drawings are to be considered as illustrative rather than in a limiting sense, the important and novel features of the invention being pointed out more particularlyA in the appended claims.

In the accompanying drawings: Fig. 1 is ya. longitudinal sectional view of my improved clutch mechanism showing the parts in Y engaged position.

Fig. 2 is atransversesectional view taken on 'me une z -z or Fig. 1.

Fig. 3 is a longitudinal sectional view of the clutch showing the parts in a disengaged position.

Fig. 4 is a structural detail of the clutch collar and shifting nger assembly of the friction clutch.

Fig. 5 is a detail view of a friction clutch finger. Fig. 6 is a longitudinal sectional view of a modied form of my invention showingthe clutch parts in engaged position. y

Fig. 7 is a fragmental elevation of the friction clutch band and operating mechanism therefor Y of the clutch shown in Fig. 6. f

Y Fig. 8 is a detailvlew of the drive arm for the friction clutch of Fig. 6.

Fig. 9 is a perspective view` of the block used vto transmit. the force to the toggle mechanism included in the operating mechanism of the clutch in Fig. 6.

Referring more particularly 'to the accompanying drawings, the reference numeral I is used to indicate generally a shaft associated with a primemover (not shown) and upon which is mounted a nya-wheel 2 usually associated with zoY 'IiiA vsuch prime mover shafts, and which in this case is used as the driving member of the clutch mechanism. The driving member is secured to the drive shaft I by means ofailange 3 and screw bolts I.

A'I'he ily-wheel 2 is. provided with an axially rearwardly extending rim section in which is formed a Pelipheral series of fluid buckets or the usual manner.

pockets! each of which has a hole ordnet l communicating'with the centrall recessed portion of the driving member. A driven shaft l is PrO- vided and is suitably supported in. alignment with the driven shaft I by bearing members l 4and I0. Thevdriven shaft Ils provided with a spirally or helically splined section Il upon which is mounted a driven clutch member Il, said member forming with the driving member 2 the driving and driven members of the fluid clutch mechanism hereinbefore referred to. The clutch member I4 comprises a splined hub 2l, which is mounted on the section I3 of the shaft 8, and radially extending spokes 6I! which join said hub 28 with an axially'forwardly extending rim section which telescopes around the rim section of the clutch member 2 and is provided with a complemental peripheral series of fluid buckets or pockets I5.. 'I'he hub 28 of thedriven clutch member I4 is provided with an annular groove 29 to receive a shifting fork 30.'. 1 f f splined portion of the driven shaft to prevent relative rotation between the shaft and disks' in The disks I6 and I1 of the friction clutch'are disposed on opposite sides of and engage opposite faces of an intermediate driving clutch disk 3l which hasv a peripheral series of teeth or splines 32 which operatively teeth or splines 'I provided on the inner periphery of the rim section of the driving clutch member 2. The clutch disks I6 and I I at the inner periphery are provided with a series of pockets or recesses designed to support and housea series of coil springs I8 for the purpose of mainengage and mesh with a cooperating series of taining the disks normally spaced and out of engagement with the cooperating driving faces of the drive disk 3l., The separation of the disks I6 vand II islimited by the. engagement of the faces of these members with a.v shaft nut I 9 located at the forward end of the longitudinal splines II and a threaded collar 20 (hereinafter described) located at the rearward end of the said longitudinal splines II of the driven shaft 8.

AThe driving clutch plate Il is provided on' its opposite sides with friction surfaces and 34 for engagingrthe disks I64 and II.

Referring to Figures 3, 4, and 5 of the drawings, it' is to be noted that the driven shaft I f isl provided witha raised threaded section I2 disposed between the longitudinal splines II and the helical splines I3. A threaded collar 20 l mounted on'the threaded portion I2 is provided withaseriesof projections 2| for rotatably mounting a series of friction clutch operating-fingers 22. Each friction 'clutch'operating .finger 22 is provided with a protuberance 26 nearthe end attached to the threaded collar 21| and also pro'- vided with a pin 25 at the other end of said friction clutch finger. 'I'he irmer web portion of the driven Amember I4 isprovided with a plurality of surfaces 23. so arranged with a pluralityof lugs 24 to provide recesses to. receive the pins 25 of' friction clutch'ingers 22- and control the 75 the 'movement 'of-.said fingers when vthe driven clutch member JI4 is .moved longitudinally on the driven shaft 8. The lugs 24 arevsecured tothe driven clutch member I4 by bolts 21.

A fluid-tight housing l encloses the entire clutch mechanism and provides a container for the operating fluid. A hand holev and a cover plate.38 are providedin the housing 35.

With reference lto the alternate construction shown in Figures 6, 7, 8, and 9, the same reference numbers are used to indicate the parts common to both constructions. A drive arm 31 is keyed tofthe driven shaft 8and provided with bifurcated ends 38 and 38. A collar 48 is loosely mounted on the driven shaft 8 between thev driving arm 31 and the fluid driven member |4. The collar 48 has pivotally secured to it yokes 4| and The yokes 4I and 42 carry, respectively, members 43 and 44 in a manner to provide for suitable adjustment thereto. A split spring band 45. having secured thereto a suitable frictional surface 48, is mounted in a position for engagement with a clutch drum provided on the inner periphery of the rearwardly extending thickened rim section' of the driving clutch member 2. A shoe 41 is secured to the split spring band 45 at or near its Central portion and is slidably mounted in the bifurcated part 379 of the drive arm 31. The shoe 41 is pivotally secured to the member 43 in a manner which will produce a toggle action as hereinafter described. Abock 48, having a plurality of surfaces 49A and l58, is pivotally secured to the member 44 and is slidably'mounted in the bifurcated part 38 of the drive arm 31. The shoe1 41 is provided with surfaces similar to the surfaces 49 and 58 of the block 48. The block 48 and the shoe 41 are pivotally secured to the members 44 and 43 respectively in such a manner as to produce a toggle action. A-pair of shoes 53 and 54 are secured to the ends ofthe split spring band and said shoes are pivotally connected to the block 48 by a pair of secondary toggle arms 5I and 52. A pair of tension springs 55 and 58, having one of the ends of each spring secured near the hub portion of the drive arm 31 while the other ends of the said springs are at tached respectively to the members 41 and 48, and normally hold the split spring band in a retracted position` .g

In the operation of this clutch mechanism it is essential that the housing 35 contain a quantity of fluid sufficient to submerge the lower pockets and extend above the lower part of the inner periphery of the driving member 2. During the rotation of the prime mover and the driving member 2, the fluid in housing 35 will flow by centrifugal action through the holes 8 into the pockets 5 and be thrown by centrifugal action against the pockets I5 a force equal to the centrifugal force of the weight of the fluid contained in the pockets 5 thereby causing the driven member I4 and the driven shaft 8 to rotate.

Referring to Figure 3 which shows the clutch in its disengaged position. it will be noted that the fluid driven member I4 is completely removed from operative relation with respect to the fluid driving member 2. The fluid driving member 2, which in thisl application is incorporated in the flywheel of the prime mover, is rotating at engine speed. On movement of the shifting fork V38 towards the prime mover, the fluid driven member I4 is gradually brought into operative or driving relation with the fluid driving member 2 so that the oil being thrown from the pockets 5 in the fluid driving member 2 contacts the insired.

It will be noted'that the splines I3 are arranged helically on the driven shaft 8, so that the resistance of the shaft 8 to rotation will tend to draw the fluid driven member I4 into closer driving relationwith driving member 2. Thus, when the fluid driven member I4 is only partially engaged, the torque exerted is comparatively. small; the force tending to advance the fluid driven member I4 towards the prime mover is likewise small and readily controlled by the shifting fork 38.

Referring still to Figure 3, it will be noted that the friction clutch members I8, I1, and 3| are disengaged, the driven members I8 and I1 thereof beingheld apart by the springs I8. The longitudinal motion` ofthe frictional driven members I8 and I1 is, however, restricted by the engagement of the faces of these members with the threaded collar 28 and the shaft nut I8 respectively. When the fluid driven member I4 has been moved into completed driving relation with the fluid driving member 2 as shown in Figure 1 all of the tangential force of the oil from the pockets of the fluid driving member 2 is being exerted against the `fluid driven member I4 which will then be rotating at a speed slightly less than that of the driving member 2 because of the slipping characteristics of the fluid clutch. In tlrls position the clutch fingers 22 are raised to the poi sition shown in Figure l and the protuberances 28 bear on the friction clutch disk I8, forcing the driven clutch disks I8 and I1 into contact withv the friction surfaces 33 and 34 of driven clutch disk 3|. When the fluid driven member I4 is in this position, a large proportion of the driving torque is being exerted on the driven member so 'that the force tending to advance the driven member towards the driving member is increased.

J This force, multiplied by the leverage of the clutch levers or flngers22 and the cam action due to the location of the protuberances 28, exerts sumcient force on the driving disks I8, I1, and 3|, to take up the slip between driving member 2 and driven member I4 and to frictionally transmit the full driving torque.

Adjustment for possible wear on the frictonal surfaces is accomplished by removing thelugs 24 through the open spaces between the spokes 88 of the clutch member I4 (see Fig. 2) and the hand hole 38.and rotating the collar 28 with its associated parts on the raised threaded portion I2 to advance protuberances 28 of the fingers 22 toward the clutch disk I8.

Referring to the` alternate construction shown in Figures 6, 7, 8, and 9, it will be readily understood that when the fluid driven member I4 is in its engaged position, it will through the action of the helical splines I3 exertA a; longitudinal thrust on the collar 48 towards the driving member 2. Such longitudinal thrust exerted through the yokes 4I and 42 and members 43 and 44 will produce a toggle action on the shoe 47|, at the central portion of the split spring band 45, and causethe frictional 'surface 48 to contact the inner periphery of the driving member 2, and simultaneously, through a secondary toggle action, the toggle arms 8| and 52 will spread the shoes 53 and 54 and ent of the split spring band 45 and the friction surface 48 so that the entire.I llfriction surface I6 will be in contact with the inner periphery -of the driving member 2, with sufficient force to frictionally transmit the full driving torque.

lAdjustment for possible wear on the frictional surfaces is accomplished by adjusting the members 43 and 44 with respect to their respective yokes Il and 42.

- It will be noted that the helical arrangement of the 'splines I3 also causes a force to act on the driven member Il away-from the driving member 2 when the resistance of the driven shaft 8 is lowered sumcientlyto permit it to overrun the prime mover or driving member 2, so that the driven members will be thrown into disengagement. This action will automatically disengage the clutch when the throttle of the prime mover is closed.

In the sequential operation of the primary hydraulic clutch members and the secondary friction clutch members during the coupling of the driving shaft and the drivenshaft, the engagement of the secondary friction clutch member is begun at the completion of the movement of the primary hydraulic clutch members into the position of driving relation; and in the reverse operation, or that of uncoupling the driving shaft and the driven shaft, the movement of the primary hydraulic clutch members out of the position of driving relation with each other is begun at the completion of disengagement of the secondary clutch members.

Although I have illustrated two applications of a friction clutch in' combination .with a fluid clutch, it is obvious ,that the principles of this invention may be employed in the application of various forms of equalizing, self-energizing or otherdevices used in connection Jwith friction and mechanical clutches, and with many other forms of friction and fluid clutches. As far as the operative principle is concerned, the problem is merely one of combining the friction clutch or other mechanical 'grlpping'device with a fluid clutch in such a way that the friction clutch or its equivalent is brought into engagement at or near the point of full engagement of the fluid clutch. This invention, therefore, contemplates such structural modifications as are necessary to embody the principles herein set forth in suitable combinations of fluid and friction clutches.

Having described my invention, what I claim as new and wish to secure by Letters Patent is:

l. A fluid operated torque transmitting mechanism including a fluid-tight casing adapted to contain a working fluid, a centrally recessed'driving member having in its outer periphery a series of'outwardly opening pockets, radially extending intake fluid ducts connecting the recessed portion of said driving member with said pockets, a driven member surrounding the driving member and having' in its inner periphery a series of inwardly opening pockets, said outwardly and inwardly opening pockets being lso arranged that the rotation of the driving member will cause the fluid contained within its pockets to be thrown tangentially into the opposing pockets of the driven member.

2. A fluid operated torque transmitting mechanism includingl a fluid-tight casing adapted to contain a working fluid, a centrally recessed driving member having in its outer periphery a series of outwardly opening pockets, radially extending Vintake fluid'ducts connecting therecessed por- V'tion of said driving member with said pockets, a driven member surrounding the driving member and having in its inner peripherya series of inwardly opening pockets, said outwardly@and" -A inwardly opening pockets'being so arranged thatv the rotation of the driving member will cause the fluid contained within its pockets to be 4thrown tangentially into the opposing pockets .of the driven member, said driving and drivenmembers being mounted for relative axial displacement f -I with respect to each other and means for rela` i tively moving the driving and driven members axially.

3. A'fluid operated torque transmitting mech-f anism including a fluid-tight casing adapted to contain a working fluid, a centrally recessed driving member having in'its outer periphery a series of outwardly opening pockets, radially extending intake fluid ducts connecting the recessed portion.` of said driving member with said pockets, a driven member surrounding the driving member and having in its inner periphery a series of inwardly opening pockets, said outwardly and inwardly opening pockets being so arranged that the rotation of the driving member will cause the fluid contained within its pockets to be thrown tangentially into the opposing pockets of the driven member, said driven member. mounted for axial displacement with respect to the driving member, and means for' moving thedriven member axially with respect to the driving member.

fi. lA fluid operated torque transmitting mechanism including a fluid-tight casing adapted to.

contain a working fluid, a circular driving member having in its outer periphery a series of outf wardlly opening pockets, a driven shaft, a driven member mounted on said shaft provided with a laterally extending periphery having a seriesof inwardly opening pockets, said inwardly openingpockets being so -arranged that .the rotation. of

the driving member will cause the fluid contained l 5. A fluid operated torque transmitting mecha-4 nism including a fluid-tight casing .adapted to contain a working fluid, adrivihg member having in its outer periphery a series of outwardly opening pockets, a driven shaft, a driven member mounted on said shaft, said driven member surrounding the driving member and having inits inner periphery a series of inwardly opening pockets, said outwardly and inwardly opening pockets being so arranged that the rotation of the driving member will cause the fluid contained within its pockets to be thrown tangentially into 'the opposing pockets of the driven member, said driven r member and driven shaft being provided with cooperating helical splines, thesaid helical splines providing for a rotating. axial displacement of the driven member with respect to the driving member, and means for effecting the rotary axial displacement of the driven member on the said helical splines with respect to the driving member.

6. A fluid operated torque transmitting mechanism including a fluid-tight casing and comprising a driving member having in its outer pcriphery a series of outwardly opening pockets, a driven shaft, a driven member` mounted on said driven shaft, said driven member surrounding the driving member and having in its inner periphery a series of inwardly opening pockets, said outwardly and inwardly opening pockets being so arranged that the rotation of the driving member will cause the fluid contained within its pockets to be thrown tangentially into the opposing pockets of the driven member, said driven member and driven shaft being provided with helical splines for automatic rotary axial engagement with and separation from the driving member, said automatic axial movement being effected by the i'luid drag between the driving and driven members and said helical splines of the driven shaft.

7. A fluid operated torque transmitting mechanism including a fluid-tight casing and comprising a driving member having in its outer periphery a series of outwardly opening pockets, a driven member surrounding the driving member and having in its inner periphery a series of inwardly opening pockets, said outwardly and inwardly openingpockets being so arranged that the rotation of the driving member will cause the fluid contained within its pockets to be thrown tangentially into the opposing pockets of the driven member, said driving and driven member defining a central recess, small holes or ducts in the fluid pockets of the driving member com^ municating with the said central recess to provide passages for the entrance of operating iiuid into the said fluid pockets.

8. In a clutch structure, in combination a fluid clutch, a friction clutch having a disk directly associated with the driving member, a driven shaft provided with longitudinal splines, two opposing pressure disks slidably mounted thereon and associated with the driven member, a threaded collar mounted on the driven shaft, camming ngers lpivoted on said threaded collar adapted to operatingly engage said pressure plates to urge the same together, said threaded collarl being axially movable by rotation about thethreaded portion of the drive shaft thereby providing means for adjusting the cam action.

9. In a clutch structure, in combination, a fluid clutch, a friction clutch having a friction disk associated with the driving member, a driven shaft provided with longitudinal splines, opposing pressure disks slidably mounted thereon and associated with the driven member, a threaded collar mounted on the driven shaft, camming fingers pivoted on said threaded collar and operatively engaging said pressure disks to urge the same together, the other end of said camming fingers being connected with the driven member of the uid clutch.

10. In a clutch structure, in combinatiom a fluid clutch, a friction clutch including adriving member and a driven member, saidjdriven mem-f ber comprising a split spring band having a suitable friction surface, a driven shaft, a collar slidably mounted on the driven shaft, adjustable links connecting the split spring band and the prising a primary iiuid clutch including an im- 2,1ce,9e1 i peller directly associated with the .driving shaft, a rotor telescoping said impeller and axially movable into and out of driving relation therewith on splines of the driven shaft, a secondary friction clutch` operatively coupled to said driving and driven shafts and means for operatively connecting said clutches whereby the secondary friction,

13. Avuid operated-'torque transmitting inech- A anism including a fluid-tight casing and comprising a driving member having in its outer periphery a series of outwardly opening pockets,a driven member, a driven shaft for said driven member, said driven member surrounding the driving member and having in its inner periphery ,a series of inwardly opening pockets, said outwardly and inwardly opening pockets being so arranged that the rotation of the driving member will cause the fluid contained within its pockets to be thrown tangentially into the opposing pockets of the driven member, said driven member4 and driven shaft being provided with cooperating helical splines, and a means in operativev engagement with said driven member for producing a rotary axial displacement of the driven member with respect to the driving member on said helical splines for producing engagement and separation of said driving 'and` driven members.

14. In combination, al driving and a driven shaft, and a clutch mechanism therefor, comprising a primary fluid clutch including an impeller directly associated with the driving shaft and a rotor telescoping said impeller capable Aof rotary and axial movement on said driven shaft, a secondary friction clutch connecting. said driving and driven shafts, means for producing initial engagement and disengagement of said clutches, a helical spline connection between the driven member and the driven shaft for automatically controlling progressive engagement and disengagement of said clutches, and means for causing the initial engagement of the driven and driving members of the uid clutch.

' 15. A torque transmitting mechanism comprising telescopic hydraulic drivingand driven members, normally out of driving relation, means adapted to effect telescopic coupling of said hydraulic members Vto bring them into driving relation, frictionally operated driving and driven members normallyv out of driving relation and means controlled by one of said hydraulic members and coacting with one of said friction members to bring the friction members into driving relation after the hydraulic member has been telescoped sufdciently to establish a driving relation therebetween, and' to effect the disengagement of said friction members before the driving relation between the hydraulic members has been disrupted.

JOHN w. Mn SH. 

